This invention relates generally to a package for dispensing a water sanitizing chemical. More specifically, it relates to a halogen containing compound that is encased in a tightly fitting material which has openings on opposing ends to permit dissolution of the halogen compound containing chemical.
A persistent problem in treating bodies of water with sanitizing chemicals has been the ability to provide a dispensing package that permits uniform distribution of an available halogen, such as chlorine, into the surrounding body of water over a predetermined period of time in a simple and reliable manner. Attempts to simply obtain this uniform distribution from dispensing packages for water sanitizing chemicals have led to the use of pressed tablets in forms varying from sticks to elliptical briquettes to circular or generally cylindrical blocks. Means have been devised to meter the sanitizing chemical whatever its form into the surrounding water.
Some of these metering means have included the use of a porous matrix of material to secure the chemical tablets and enclosing the porous matrix material and chemical tablets with a water impermeable synthetic material on the top and sides. Water permeates the porous underside of the matrix by osmosis and gradually dissolves the available sanitizing chemical into the surrounding water. However, an approach such as this has little control over the dissolving rate of the packaged chemicals.
Another approach uses a tablet of available chlorine containing compound that has two substantially parallel faces secured to a generally perpendicular cylindrical exterior surface that is covered with an impervious film secured to the tablet by means of a suitable adhesive. One of the parallel plane faces could also be covered by this same impervious material. This simple dispensing package is effective, but tends to be relatively costly because of the adhesive and results in an overly fast dissolving rate of the sanitizing chemical when calcium hypochlorite is employed.
Shrink wrap material, either water shrinkable or heat shrinkable, has been employed in an attempt to provide a simpler, less costly means of adhering a covering to the water sanitizing chemical. One approach uses heat shrinkable material to encase a plurality of tablets which could be cut to the desired length and placed in a strainer basket of a swimming pool skimmer unit. This provides a generally uniform dissolving rate but, apparently because of the flat ends, results in a relatively rapid dissolution of the encased sanitizing chemical.
The need for a simply packaged water sanitizing chemical that releases available chlorine at a relatively uniform rate over a long predetermined period is solved by the present invention which uses an encased tablet with obliquely tapered ends and openings in the tapered ends of the casing or shell to permit controlled release of the dissolved chemical to the surrounding water.